how do you calculate box sixe?

[CB7tuner]

does anybody have the formula to calculate the dimensions of a box? i just bought 2 12" power acoustik fubar subs (1800 watts). i have them in a dual bandpass box right now but they sound like shit and not that loud. i have a 3000 watt amp to. they say they need 1.2 cubic feet air space in a sealed box. what would the dimensions be for a box that size i could build? thanks

[MachNU]

okay first you have to get the min and max aloud air space for the speaker then do Length * Width * Height = "Your Number" / 1728. Then with your final number like a deciaml number 1.* or 2.* or even 3.* then multiple that number by the thickness of the wood you are using.

Like for mine when i built it...it was 42 * 13 * 9 = 4914 / 1728 = 2.843 * 3/4 = 2.13 Which was the cubic feet of my box.

Then after you get your number divided that will show you what cubic feet you have! For min when i did mine i had to be between 1.75 cubic feet and 2.25 and ended with 2.1. Its really simple!

Hope that helps!

[BanginJimmy]

If you just want to build by manufacturers specs, then take that 1.2 and multiple that by 1728. With that number add the displacement of the subs you want.

with that number divide it by the max width you want the box (width of the trunk - 1.5" for the wood). Divide that number by the height you want the box - 1.5". the number left is the depth of the box (inside dimension, so you add 1.5" to get your outside dimensions. Height or width may have to be shortened slightly to get enough depth to fit your subs.


for example your trunk is 38" wide and 17" tall. SO when your getting your dimensions, you would want to divide your total airspace by 36.5 for width and 15.5 for height.

[MachNU]

If you just want to build by manufacturers specs, then take that 1.2 and multiple that by 1728. With that number add the displacement of the subs you want.

with that number divide it by the max width you want the box (width of the trunk - 1.5" for the wood). Divide that number by the height you want the box - 1.5". the number left is the depth of the box (inside dimension, so you add 1.5" to get your outside dimensions. Height or width may have to be shortened slightly to get enough depth to fit your subs.


for example your trunk is 38" wide and 17" tall. SO when your getting your dimensions, you would want to divide your total airspace by 36.5 for width and 15.5 for height.

wow that seems way more confuzing than what i said, but still works if your looking to fill the most of your trunk!! :goodjob:

[BanginJimmy]

I cant help it, I absolutely hate seeing a box that just sits inside a trunk without blending at all.

[MachNU]

I cant help it, I absolutely hate seeing a box that just sits inside a trunk without blending at all.

LOL hey for me thats what i did and it looks dam good, But i also worked with a square box when i built it to kinda look blended. But thats also becuase i did the base of the trunk and the speaker to match each other. I dont have the tools as home to get really really in-depth!

[Kyle]

A calculator. Just kidding I used Autocad for my two chamber slanted box, I think it told me. Good luck, but I hear there is room for error.

[BanginJimmy]

hello 4 month old thread

[2.0civic]

LIRL